Answer:
A ball is thrown at an initial height of 5 feet with an initial upward velocity at 29 ft/s. lets assume that balls height h (in feet) after t seconds is give by:
<u>h= 5 + 29t -16t^2</u>
Explanation:
h= 5 + 29t -16t^2
a time when the ball's height will be 17 ft
17 = 5 + 29t -16t2
0 = -17 + 5 + 29t -16t2
0 = -12 + 29t - 16t2
Using the quadratic equation:
t = (-29±√(292-(4*(-16)*(-12))))÷2(-16)
= (-29±√(841 - 768))÷(-32)
= (-29±√(73))÷(-32)
= (-29 + 8.544)÷(-32) or (-29 - 8.544)÷(-32)
= (-20.456)÷(-32) or -37.544÷(-32)
= 0.64 or 1.17
So, the ball is at a height of 17 ft twice: once on the way up after 0.64 seconds and once on the way back down after 1.17 seconds.
Answer:
a. 2 Hz b. 0.5 cycles c . 0 V
Explanation:
a. What is period of armature?
Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz
b. How many cycles are completed in T/2 sec?
The period, T = 1/f = 1/2 Hz = 0.5 s.
So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,
Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.
c. What is the maximum emf produced when the armature completes 180° rotation?
Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0
E = E₀ × 0 = 0
E = 0
So, at 180° rotation, the maximum emf produced is 0 V.
The time it would take a 2500 W electric kettle to boil away 1.5 Kg of water is 2400 seconds
<h3>How to calculate the time</h3>
Use the formula:
Power × time = mass × specific heat
Given mass = 1. 5kg
Specific latent heat of vaporization = 4000000 J/ Kg
Power = 2500 W
Substitute the values into the formula
Power × time = mass × specific heat
2500 × time = 1. 5 × 4000000
Make 'time' the subject
time = 1. 5 × 4000000 ÷ 2500 = 6000000 ÷ 2500 = 2400 seconds
Therefore, the time it would take a 2500 W electric kettle to boil away 1.5 Kg of water is 2400 seconds.
Learn more about specific latent heat of vaporization:
https://brainly.in/question/1580957
#SPJ1
Answer:
the law of motion
Explanation:
because the wheels are moving it means motion i am not sure which number law it is but I believe that it is 2nd but u should look it up to be safe
Answer:
Answered
Explanation:
The radius of curvature of the mirror R = 20 cm
then the focal length f = R/2 = 10 cm
(a) From mirror formula
1/f = 1/di + /1do
then the image distance
di = fd_o / d_o - f
= (10)(40) / 40-10
= 30.76 cm
since the image distance is positive so the image is real
ii) when the object distance d_0=20 cm
di = 10×20/ 20-10
= 20
Hence, the image must be real
iii)when the object distance d_0 = 10
di = 10×10 / 10-10 = ∞ (infinite)
the image will be formed at ∞
here also image will be real but diminished.
